1. Field of the Invention
The present invention relates to an oil separator for separating oil from an oil and refrigerant gas mixture in a chiller system. More particularly, the invention is directed to a vertical oil separator having a baffle for separating oil from an oil and refrigerant gas mixture in a chiller system.
2. Background of the Invention
In general, a refrigeration or chiller system has a compressor to compress a refrigerant gas, a condenser to condense the compressed gas to a refrigerant liquid by cooling the gas, an expansion valve to reduce pressure of the refrigerant liquid, and an evaporator for absorbing heat from a fluid to provide a chilled liquid for refrigeration of a desired area. There are various types of compressors used in a chiller system. For example, screw, reciprocating, centrifugal, or scroll compressors are well known in a chiller system.
Typically, a compressor uses oil to lubricate and provide better sealing performance in the compressor. Inevitably, the oil used in the compressor becomes mixed with the refrigerant gas, and the mixture of the oil and refrigerant gas is carried from the compressor to the condenser and to the evaporator.
However, oil does not have as good heat transfer capability as refrigerant, and the oil traveled into the condenser and the evaporator reduces the efficiency of the chiller system.
Furthermore, if the oil traveled from the compressor to the other parts of the chiller is not returned to the compressor, more oil needs to be added to the chiller system to maintain the compressor performance, or the lack of oil causes the compressor to fail. Typically, in a screw compressor, several gallons of oil per minute are required to circulate with the compressed refrigerant gas in the compressor to lubricate and seal compressor rotors.
In an effort to alleviate the above problems, it is known to provide an oil separator between the compressor and condenser in a chiller system. An oil separator basically separates oil from an oil and refrigerant gas mixture from the compressor, discharges the refrigerant gas to the condenser, and returns the separated oil to the compressor.
Various oil separators are known for separating oil from an oil and refrigerant gas mixture. However, many oil separators suffer from deficiency in performance, manufacturing cost, size, and compatibility to the existing chiller system.
Thus, it is desirable to provide an oil separator that provides excellent oil separation performance, that is cost effective, compact in size, and compatible to the existing chiller system design, and that can be readily manufactured. The present invention is directed to solving one or more of the shortcomings associated with prior art designs.
In accordance with the invention, a device is provided for separating oil from an oil and gas mixture in a chiller system. The device includes a housing having a peripheral wall, an oil and gas inlet, a gas outlet, and an oil outlet. The device also includes a baffle defining a first chamber and a second chamber within the housing, the first chamber being in fluid communication with the oil and gas inlet, and a coalescing assembly defining a third chamber and a fourth chamber within the housing, the fourth chamber being in fluid communication with the gas outlet. The device, further, includes an oil sump portion disposed within the housing, the oil sump portion being in fluid communication with the oil outlet.
In another aspect, a device for separating oil from an oil and gas mixture in a chiller system, includes a housing having a peripheral wall surrounding a top chamber, a bottom chamber, and an intermediate chamber between the top and bottom chambers. The device also includes an oil and gas inlet attached tangentially to the housing to impart a swirling motion to the oil and gas mixture in the intermediate chamber, a gas outlet extending from the top chamber through the housing to discharge the gas in the top chamber outside the housing, an oil outlet in fluid communication with the bottom chamber, and a baffle disposed in the intermediate portion, the baffle having a baffle wall to separate the oil from the oil and gas mixture by forcing a flow direction of the oil and gas mixture to change in the intermediate portion.
In another aspect of the invention, a method is provided for separating oil from an oil and gas mixture in a chiller system. The method includes tangentially introducing the oil and gas mixture into a housing, separating the oil from the mixture by centrifugal force, separating the oil from the mixture by changing a flow direction of the mixture in the housing, discharging the gas from the housing, and discharging the oil separated from the oil and gas mixture from the housing.
It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the invention, as claimed.